After imbedding parameterizations of Feynman integrals in projective space,
we formulate the Feynman integrals as hypergeometric functions over Grassmannians.
Taking Feynman integrals of one-loop self-energy,
massless one-loop triangle, and two-loop vacuum diagrams as examples, we illuminate
how to construct canonical series solutions from those relevant GKZ-systems [1]},
whose convergent regions of those series can be derived by Horn's study [2]}.
Finally parameterizations of two-loop self energy diagrams with three, four and five propagators
are presented respectively. Those Feynman integrals are imbedded in
the subvarieties of Grassmannians by the parameterizations directly.
To shorten the length of text, we present the hypergeometric
expressions of the Feynman integrals elsewhere. In addition,
we don't state those mathematical concepts and theorems that have been used in our analyses here,
because they can be found in some well-known mathematical textbooks [1]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}.
